Lithographic and offset printing plate



E.E.NOVOTNY.

LITHOGRAPHIOAND OFFSET PRINTING PLATE.

APPLICATION FILED DEC. 30, 1916.

1,357,340, Patented Nov. 2, 1920.

E Q. Z $HEET$SHEET 1.

E. E. NOVOTN-Y. LITHOGRAPHIC AND OFFSET PRINTING PLATE.

APPLICATION FILED DEC-30, I916.

Patented Nov. 2, 19204 2 SHEETS-SHEET 2.

UNITED STATES PATENT orries.

EMIL n. novo'rmz, or mvnnsnm, rumors, nssrenoa TO .1. sroennm. smoxns or,uoomas'rown, mew JERSEY. I

LI'I HOGBAPHIC AND OFFSET PRINTING PLATE.

Be it known that I EMIL E. Novo'rNY, a clt zen of the United tates,residing at Riverside, 1n the countyof Cook and State of Illinois, haveinvented certain new and useful Improvements in Lithographic and OffsetPrinting Plates, of which the following is a specification.

This invention relates to a printing plate which is particularly adaptedfor use in connection with various printing processes, such 'aslithographic, offset printing. and planographic work in general.

In'the present instance it is my purpose to provide a printing platewhich is formed of a material or materials 'capable of being molded orshaped to any desired form or dimensions and having a face which issusceptlble of treatment to produce a surface for the practice ofprintin processes such as curved or cylindrical and may be either thoseabove mentioned. 0 accomplish this "I have produced a plate whichembodies .or

includes a body of plastic material such as a phenolic condensationproduct having combined therewith, preferably in granular or powderedform a suitable substance, such as lithographic stone or metal,depending upon the purpose for which the plate is to be employed. Such aplate may be made of any desired shape or contour, either flat,

flexible or inflexible in its nature. In this connection I wish to statethat I realize that the invention in its broadasp'ects may be embodiedin various forms, and therefore, while I have herein shown and describeda preferred embodiment of the invention, as well as certain chosenmodifications thereof, I wish it to be understood that I do not limitmyself to these particular exemplifications, as modification andvariation may be made without departing from the spirit of the inventionor exceeding the scope ofthe appended claims.

My invention consists in the printing plate and the method of making thesame set forth in and falling within the scope of the appended claims.In the accompanying drawings:

Figure '1 is a conventional view of a press and showing a plate beingmolded therein. Figs 2 to 7 inclusive are detail views showing platesembodying my invention wherein the printing surface of each of theplates is made of a coating of powdered na-- Specification of LettersPatent. Application ni d December so, 1916. serial No.

stone must be discarded.

Patented Nov. 2, 1920. 139,721.

terial united witha backing layer of plastic material.

F 8 is a detail view partly in section showing a segmental form of platemounted on a press cylinder, the printing surface of the plate beingalso in the nature of a coatin of powdered material.

igs. 9 and 10 are end views showingv cylindrical plates mounted on pressarbors or cyllnders, the printing surfaces of these plates being alsoformed of powdered material.

Fig. 11 is a cross sectional view of a modified form of flat plate, inthis instance the powdered material being incorporatedin the body ofplastic material. I V

Fig. 12 is a similar view, but showing a cylindrical plate wherein thepowdered material is incorporated in the plastic material.

, As is well known, at the present time, in lithography the printingplate is composed of either a lithographic stone or of a metal such aszinc or aluminum. The lithographic stone plate possesses certainadvantages due primarily to its inherent porosity which enablesit toreadily hold the grease, retain the water,.and take on the desiredgrain. On the other hand, such a stone plateis naturally restricted inits use to a flat form of a particular design, work or image, and it isdesired to remove the latter from the stone in order to apply anotherdesign, work or imageeto the face of such stone, it is necessary tofollow out a tedious process of cleaning and polishing the stonesurface, this work requiring considerable care andnecessitating theemployment of an expert. Of course the frequent re-polishing andregraining of the stone naturally reduces its thickness and in thecourse of time such Metallic plates used in lithography, such as thosecomposed of zinc or aluminum, possess the advantage that they may beemployed on rotary presses, di1e to the inherent flexibility of the thinmetallic plate which enables it to be bent into form to be ap lied tothe curved surface of the cylinder. owever, such a metallic platezisincapable of taking. on the fine printing surface of a desired grain,which is attainable with the lithographic stone, and furthermore, suchmetallic-plate requires considerable expert work in the production ofthe grain for the.

printing surface because the metal is not sufficiently porous in itsnature, and consequently even when the greatest of care 1s exercised inthe preparation of the plate the inoisture-retaining qualities of thegrain is inferior to that of the lithographicstone. Thus, while it ispossible to print directly on the paper from a lithographic stone whenthe latter is resting on its flat bed, it is the present practice to usethe metal lithographic plate in doing offset work, that is to say, theimage, work or design appearing on the metal plate is first transferredto an offset roller of rubber, and then such offset roller acts directlyupon the paper to transfer the design, work or image to the latter.

As contradistinguished from the litho-' graphic stone and from the metallithographic plate, I have provided a printing plate which while havinginherent therein the advantages of both the above mentioned types ofplates it is free from the disadvantages and draw-backs ust mentioned asincident to the latter.

In Figs. 1 to 10 inclusive, I have shown a printing plate which may beused for lithographic, planographic and offset printing and wherein theprinting face of the plate is formed of a coating of powdered or scribein connectiontherewith the manufacture of the plate illustrated in Fig.2.

Referring to said Figs. 1 and 2, the numeral .1 indicates the bed of thepress while 2 is the top platen thereof, and such press is intended tobe heated and cooled in any suitable manner. Upon the bed 1 of the pressI first place a base 3 which is in the nature of a metal sheet. and ispreferably formed with a series of dovetailed apertures 4 therein. Onsuch metal base I impose a sheet 5 ot' plastic material, preferably inthe nature of a phenolic condensation product of which there are anumber of well known varieties such as bakelite or condensite. As iswell known, such a phenolic condensation product possesses markedadvantages from the standpoint of strength, durability,incompressibility and capability of retaining the shape or form to whichit has been set. In some of'its forms this phenolic material which as isWellknown is a synthetic resin when completely set assumes a hard,inflexible state and is not thereafter subject to changes even whenre-heated. In another form such phenolic material while it may be setorhardened may subsequently be reheated and re-softened to render itcapable of being again worked or flexed as may be desired. I prefer toemploy) the latter form: or grade of the material ecause While it may behardened and set by cooling to form '5 on the metallic base 3, theformer is in a relatively soft or plastic stage or condition, of almostputt -like consistency. Pressure is now applied y closing the top platen2 of the press to smooth or level the phenolic sheet, which also resultsin forcing some of the phenolic material through the dovetailedapertures or openings 4 of the plate thus forming phenolic lugs 6 whichwill lock or anchor the layer 5 to the base. At the time of applyingthis initial pressure, however, the phenolic layer is not compressed orflattened to its final thickness.

The press is now opened by raising the platen 2 and a coating or layerof powdery substance shown at 7 is now sprinkled or applied to theuppermost face of the plastic material. This granular or powderedmaterial is so applied as to provide a coating or sheet of any desiredor required thickness, the amount of the powdered or granular materialdepending of course upon the dimensions of the plate it is desired toproduce, and this may be determined as to thickness by suitable bearers8 which form aframe on the bed of the press. as will be readilyunderstood. If it is desired to produce a plate having thecharacteristics of a lithographic stone then the material employed forthis top coating 7 is in the nature of pulverized, powdered or granularlithographic stone. Under such conditions the top platen of the press isequipped with a smooth, hard, polished bottom face, such as is shown at9 so that when the top platen is again closed on the bed of thepressthis face will contact or press against the layer of granular orpulverized lithographic stone and embed the same in the upper face ofthe layer of phenolic material, thus facing this phenolic layer with aprinting face of stone which when subjected to the action of the etchand gum will readily take on the necessary gram precisely as does theordinary lithographic stone. hen, however, it is desired to form thisprinting face of the plate of granular metal, the bottom face 9 of thepress platen 2 may be grained, so that when the pressure is applied toembedthe metallic particles in the plastic layer, the graining of thebottom face of the platen will be reproduced on the metallic coating 'orface of the plate thus obviating the necessity of subsequently grainingthis metallic face to produce the necessary tooth as is required now inthe preparation of metallic lithographic plates. Under some conditionssecond stage of of this face, asis required with the ordinary metalplate will not be necessary, as the etch acting on the lithographicstone particles will givethe face the necessary tooth or grain and willincrease the water retentive qualities of the metallic surface. Ofcourse in employing both V the powdered lithographic stone and thegranular or powdered metal, care should be taken, to see that these areclean and sensitive before bein applied I to the plastic or henoliclayer. en this the making of the plate has been completed through heat,pressure and cooling while such plate is in the press, the press may beopened and the plate removed, such plate having been of course permittedto remain in the press preferably a sufficient length of time to set orharden to an inflexible form. When removed, the plate will appear asshown in Fig. 2. Of course when it is to be used in actual work the face7 is treated or operated upon in the usual manner. That is to say, theimage or work is I applied thereto as is ordinarily done with thelithographic stone. t In Fig. 3 instead of anchoring the plastic layer 5to the base through lugs or openings as is done in Fig. 2, such plasticlayer may be cemented directly to the base, or a suitable binderindicated at 10 may be used. InFig. 4 the base3 is made of a fibrousmaterial such as compressed paper pulp preferably, impregnated with aphenolic ma terial andon this base the plate 5 carrying the powderedface is. cemented. If the fibrous plate-3 be impregnated with asufficient amount of the. phenolic material it will not be necessary toemploy the layer 5, but the powdered facing may be applied directly tothe sheet 3. Y I I In Figf -fiinstead of employing a separate base, aplate 5 of phenolic material, of suitable thickness is employed and'thepowdered facing 7 isapplied directlyto this as before described. a I

In Fig. 6 a base'31of plastic material has the pow ered' facing 7applied thereto, while theopposite face of this base 3" is-formedwith""bosses 11 which; seat in recesses 12 formed'onthe block support13, the bosses and recesses being arranged predetermined and spaceddistances apart so that the plate may be positioned and arranged on thesupport.

In Fig. 7 a metallic back 14 is employed which is in the nature of ashell-like plate having an aperture as at 15 and recesses or depressions16 formed in the upper face thereof, the phenplic layer 17 being applieddirectly to this face, such phenolic plate 17 having bosses 18 molded onthe under face thereof which seat in the recesses 16 and havin a lug 19molded through the opening 15. f course the powdered facing 7 is appliedto this phenolic layer 17.

Such a plate as. is shown in Fig. 7. may be curved or bowed intosegmental form to fit on the cylinder 20 of a press, such cylindercarrying pins 21 which projectthrough remetallic base 14 of the plate tohold such plate against the cylinder by magnetic attraction.

In Fig. 9 I have shown the, plate of cylindrical form, this plate in itscomponent arts bein substantially the same as that s own in 1g. 5, thatis to say, is formed of a cylinder 24 of plasticmaterial having the facecoating 251 .of a powdered substance, the complete tubular orcylindrical .plate being fitted oversa cylinder or arbor 26 forming apart of the press. In this instance the plate may be first made in flatform and then while still warm and capable of being flexed may be rolledinto cylindrical shape about a suitable mandrel. Or if desired, theplate shown in Fi 9 may be cast or molded in cylindrical s ape. I

In Fig. 10 a. metal shell 27 carries the'phenolic layer 28, the latterin turn'carryingthe printing face or coating of the pulvemzed material,as shown in 29, these being fitted uponthe cylinder 30 of the press. 7

I In Fig. 11 the powdered material instead ofbeing applied inthe form'ofa facing coating is intimately commingled' with the body of plasticmaterial 31, as is indicated m .Callly produced by excee ing y slmplemethods' and the deslred designs may be readily lpplied to, andwhen-desired, removed from a t e printing surface. of the plate, andfurthermore, during the course of it s-manufacture the plate may beshaped to accommo-' te itself to any supporting body, such as thecylinder of a printing press. Further more, I am enabled to produceplates of any desired contour and hardness or rigidity,

and may employ as facings for the plates, or as component parts thereofintimately incorporated therein, any suitable powdered operation.

for the printing of the required number of material. The printing facesof my plates may be produced by a simple method of molding with either ahighly polished smooth and plane surface of stone, or any desired grainor tooth such as is at present in the art produced by the usual grindingAfter.my plate'has been used impressions the printing face thereof maybe removed or cleaned by scraping and the plate again re-surfaced withthe powderedmaterial and the plate is thus again ready for other anddifi'erent printing matter if my plates on a rotary press or inconnection with a rotary ofi'set press or to use any combination ofplates on such a press to produce work which resembles eitherlithographic printing or offset printing. This is made possible throughthe use of my improved plates which are of uniform thickness or heightto paper, of uniform grain and of strong, substantial cross sectionsothat they may be clamped or'mounted in any desired interchangeablecombinations.

Furthermore, I amenabled to produce on a rotary press work showinggreater graduations of tints and full tones than is atpresent ossible inthe art due to my printing sur ace being capable of any desired amountof-curvature to form a curved lithographic stone or a metallic surfacehaving incorporated therewith granules or powder of lithographic stone,kaolin or other water retentive or absorbent, materials. This brings ina new field of possibilities in rotary printing as it eliminates theshortcomin s of the flexibleametallic plate which ma e rotaryplanographic. printing possible but which depends entirely on the grainor tooth V for their water retentive qualitles. Furthermore, with thispossibility of increased water retentive qualities this plate is capableof printing by direct contact with paper on a rotary ty e of machine, asis now done in the art with flat, lithographic stone.

What I claim is:

1. A lithographic and ofiset printing plate comprising a body portion,including a synthetic resinous material, and a printing face for.the'body portion composed of gran;

ular particles and forming a lithographic and oiiset printing surfacebonded to 'the I body portion by thesynthetic resinous material.

2. A lithographic and offset printing plate comprising a body portion,including a synthetic resinous material, a toothed printing face for thebody portion composed of granular particles and formin a lithographicand oiiset printing surface bonded to the terial,,and a backing uponwhich the body portion is mounted.

3. A lithographic and offset printing plate comprising a fibrous bodyimpregnated with a, synthetic resinous material to reinforce such body,and a granular printing face composed of granula particles and form-'ing a lithographic and ofi'set printing sur-' face bonded to the bodyby the synthetic resinous material. &

4. A lithographic and offset printing plate comprising a fibrous body, agranular printbody portionby the synthetic resinous mar ing faceforming-a lithographic and oiiset printing surface, and a hard and setsynthetic resinous material bonding the granu-.

vlar printing face to the fibrous body.

In testimony whereof I afiix my signature.

EMIL E. NOVOTNY.

